The present invention relates to an automatically fastening seatbelt assembly which causes an occupant of a vehicle to be automatically held to a seat in the vehicle by restraining webbing after the occupant is positioned in the seat in the vehicle. The seatbelt assembly includes a guide rail, a slider which is displaceable along the guide rail and restraining webbing which is fixed to the slider at one end thereof. The guide rail is provided with stop switches at both ends thereof, the stop switches being connected to a source of electricity or an electric control circuit through connecting wires. The stop switches detect the arrival of the slider at either end of the guide rail and generate signals indicating the same to the electric control circuit. More particularly, the present invention relates to improvements for adjusting the position of an anchor plate to fit the restraining webbing to the occupant by utilizing an adjusting means. The adjusting means overcomes fitting problems arising because a small occupant cannot otherwise properly be held to the seat by the restraining webbing.
A similar seatbelt assembly is disclosed in U.S. Pat. No. 4,343,489 (Suzuki et al.), which teaches a seatbelt system which includes a guide rail having a longitudinal guide groove therein. The guide rail is fixed on a roof side member of a vehicle, and a slider slides within the guide groove and is displaceable along the guide rail. The slider is connected to one end of a restraining webbing by an anchor plate.
Suzuki et al.'s anchor plate includes a recess and the slider includes a projection which projects in a lateral direction from an edge portion of the slider to engage with the recess of the anchor plate. Accordingly, the position of the anchor plate is fixed under normal use with respect to the slider in a position which will provide the greatest comfort to the average passenger. The projection also is designed so that, when the restraining webbing has a tensile force caused by abrupt movement of the vehicle, the projection can be broken away. As a result, the anchor plate can rotate about a bolt to position the restraining webbing at the angle which can best prevent the occupant from moving due to the abrupt movement of the vehicle.
However, as noted, the normal webbing position is chosen for the average passenger. The Suzuki et al. patent does not disclose any adjusting means which can fit the restraining webbing depending on the size of the occupants. It also has the disadvantage that the projection must be replaced after it breaks off.
Another seatbelt assembly is disclosed in U.S. Pat. No. 4,473,243 (Ogawa), which teaches a shoulder webbing anchoring device including a side anchor plate, a webbing anchor plate, an anchor pin and a holder plate. The side anchor plate is fixed on a window frame by bolts and the webbing anchor plate is mounted rotatably on the side anchor plate by the anchor pin. The holder plate includes a hemispherical projection and the webbing anchor plate includes a plurality of receiving holes. Accordingly, the holder plate prevents the webbing anchor plate from rotating about the anchor pin when the hemispherical projection of the holder plate is inserted into one of the plurality of receiving holes. When the hemispherical projection of the holder plate is inserted into another of the plurality of receiving holes, the webbing anchor plate is positioned in a different position about the anchor pin so that the restraining webbing can be adjusted to fit the restraining webbing to variously sized occupants.
However, the adjusting means disclosed in Ogawa patent cannot prevent the webbing anchor plate from rotating beyond the suitable positions for restraining the occupant by the restraining webbing. Further, the Ogawa adjusting means is fixed on the window frame of a door and is not movable along a guide rail. Accordingly, the Ogawa patent does not disclose a suitable structure for an adjusting means which is mounted on a slider.